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    robbibt

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    [–] What gun fired this mystery WWII era shell casing found in Guadalcanal, Solomon Islands? robbibt 2 points ago in whatisthisthing

    Amazing, thankyou! This fits: I measured the primer end because the front is broken and distorted (on a second measure, it's around 0.77 inches with a little oxidation crusting). A few further questions:

    1) What does the "42" number represent? Production year? 2) What kind of purpose would that weapon most commonly be used for in the Pacific? Anti personnel, anti-air etc? It was found washed up on a beach, but that probably doesn't narrow things down much given fighting in the surrounding area took place on land, sea and air. 3) As an Australian with no experience with guns, is the damage at the end simply the result of the bullet being fired?

    [–] What gun fired this mystery WWII era shell casing found in Guadalcanal, Solomon Islands? robbibt 2 points ago in whatisthisthing

    About 15 years ago I found this shell casing washed up on the shore about 20 km northwest of Honiara, Guadalcanal in the Solomon Islands. The area is where some of the most intense battles of the Pacific theatre occurred during WWII, so that narrows down the approximate date. The shell casing is 0.8 inches in diameter, and has "L C 42" stamped on the base (I imagine this means American?)

    What can anyone tell me about what kind of bullet this fired, and the gun used? What does the code mean? And is the damaged end simply the result of the bullet being fired?

    [–] Canada mapped by over 5 million square kilometres of trees and forest [OC] robbibt 1 points ago * (lasted edited a month ago) in canada

    I made this as a sequel to a Forests of the USA map I recently posted, and thought /r/Canada might enjoy it! The map was made using a combination of layers from the amazing Hansen et al. 2013 datasets, and elevation data from the Shuttle Radar Topography Mission - all cleaned and prepared in the open-source QGIS software!

    For anyone who would like this as a poster, you can grab a copy here!

    [–] Canada mapped by over 5 million square km / 1.2 billion acres of trees and forest [OC] robbibt 2 points ago in dataisbeautiful

    A few weeks ago I posted Forests of the USA, and got lots of requests for other parts of the world... including literally hundreds for Canada! To make this map I used R code to download vegetation layers from the amazing Hansen et al. 2013 datasets, used a median filter to remove noise and spatial Landsat artefacts, and included local topography using a SRTM 90m resolution digital elevation data overlay. Visualised using the open-source QGIS software!

    [–] Canada mapped by over 5 million square kilometres of trees and forests [OC] robbibt 1 points ago * (lasted edited 2 months ago) in dataisbeautiful

    I believe Hansen et al. trained their models directly on Landsat bands 3, 4, 5, and 7 themselves rather than specifically calculating NDVI, but essentially a similar concept!

    [–] Canada mapped by over 5 million square kilometres of trees and forests [OC] robbibt 1 points ago in MapPorn

    A few weeks ago I posted Forests of the USA, and got lots of requests for other parts of the world... including literally hundreds for Canada! To make this map I used R code to download vegetation layers from the amazing Hansen et al. 2013 datasets, used a median filter to remove noise and spatial Landsat artefacts, and included local topography using a SRTM 90m resolution digital elevation data overlay. Visualised using the open-source QGIS software!

    [–] Canada mapped by over 5 million square kilometres of trees and forests [OC] robbibt 1 points ago * (lasted edited 2 months ago) in dataisbeautiful

    For those curious about how this kind of vegetation mapping is done: the data comes from a group of satellites called Landsat, which have been taking photographs of every 30x30 metre patch of ground on the entire planet since 1972. The photographs include the standard blue, green and red layers of light that we can see with our eyes, but also a whole bunch more that are reflected strongly by plants but are completely invisible to us (e.g. wavelengths like near infrared, short-wave infrared and thermal infrared etc).

    By measuring all these different types of light accurately, you can then teach a computer model (in this case, an aptly-named "decision tree"... but "random forest" models are popular too!) to recognise what combinations of light indicate that trees are growing below. By applying those models to every 30x30 metre patch of ground using a supercomputer, you can then map out the locations of forests and trees across the entire planet!

    [–] Canada mapped by over 5 million square kilometres of trees and forests [OC] robbibt 1 points ago in dataisbeautiful

    A few weeks ago I posted Forests of the USA, and got lots of requests for other parts of the world... including literally hundreds for Canada! To make this map I used R code to download vegetation layers from the amazing Hansen et al. 2013 datasets, used a median filter to remove noise and spatial Landsat artefacts, and included local topography using a SRTM 90m resolution digital elevation data overlay. Visualised using the open-source QGIS software!

    [–] Matplotlib+Python used to plot every single known object in the Solar System! robbibt 1 points ago in Python

    I'm just interested in obtaining xyz data similar to that contained in the "positions.txt" file... at this stage the visualizer wouldn't be required

    [–] Matplotlib+Python used to plot every single known object in the Solar System! robbibt 1 points ago in Python

    Ah, OK! If I wanted to adapt this to look at the locations of planets/objects at specific moments in time (historical or future), what would be the minimum that would need to be changed in the code? Or does the location data get drawn/downloaded from a data source online?

    [–] Matplotlib+Python used to plot every single known object in the Solar System! robbibt 6 points ago in Python

    This is amazing, u/christophertacon! Are the locations dynamic in time, or hard-coded based on a specific time-step? I'd love to explore something similar looking at the positions of various objects across time.

    I also recommend uploading this to bitbucket or github... a readme would also be fantastic to help get my head around what each bit of the code does. Really interesting work!

    [–] Sydney This Weekend (25 & 26) robbibt 2 points ago in sydney

    Randwick Council has their inaugural "Best Gift Market" at the Randwick Environmental Park this weekend too!

    http://www.randwick.nsw.gov.au/community/whats-on/events/2017/november/best-gift-markets

    [–] 24 hours of marine traffic on the Baltic Sea [OC] robbibt 1 points ago in dataisbeautiful

    They certainly do, but knowing more about what those distinguished ships actually represent would add a whole extra level to the information that can be gained from this dataviz (e.g. why do ships X behave this way? Why do ships from X go to Y? etc).

    [–] Global map of the human transportation footprint robbibt 1 points ago in u_robbibt

    Click on "View interactive sphere" on the right for the interactive version!